/*******************************************************************************
 * Copyright 2011, 2013 Chris Banes.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package com.taropan.wallpaper.widget;

import com.taropan.wallpaper.util.CacheableBitmapDrawable;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.util.AttributeSet;
import android.widget.ImageView;

public class CacheableImageView extends ImageView {

	private static void onDrawableSet(Drawable drawable) {
		if (drawable instanceof CacheableBitmapDrawable) {
			((CacheableBitmapDrawable) drawable).setBeingUsed(true);
		}
	}

	private static void onDrawableUnset(final Drawable drawable) {
		if (drawable instanceof CacheableBitmapDrawable) {
			((CacheableBitmapDrawable) drawable).setBeingUsed(false);
		}
	}

	public CacheableImageView(Context context) {
		super(context);
	}

	public CacheableImageView(Context context, AttributeSet attrs) {
		super(context, attrs);
	}

	@Override
	public void setImageDrawable(Drawable drawable) {
		final Drawable previousDrawable = getDrawable();

		// Set new Drawable
		super.setImageDrawable(drawable);

		if (drawable != previousDrawable) {
			onDrawableSet(drawable);
			onDrawableUnset(previousDrawable);
		}
	}

	@Override
	public void setImageResource(int resId) {
		final Drawable previousDrawable = getDrawable();
		super.setImageResource(resId);
		onDrawableUnset(previousDrawable);
	}

	@Override
	public void setImageURI(Uri uri) {
		final Drawable previousDrawable = getDrawable();
		super.setImageURI(uri);
		onDrawableUnset(previousDrawable);
	}

	@Override
	protected void onDetachedFromWindow() {
		super.onDetachedFromWindow();

		// Will cause displayed bitmap wrapper to be 'free-able'
		setImageDrawable(null);
	}

}
